1. Field of the Invention
This invention relates to technology for printing with two kinds of chromatic color inks which are interchangeable with one another when reproducing some colors, and which differ in lightness.
2. Description of the Related Art
To date, in monotone printing to produce a printed result like a black and white photograph, printing has been carried out using chromatic color ink in addition to achromatic color ink. For example, high density cyan ink, low density cyan ink, high density magenta ink, low density magenta ink, and yellow ink are used in color printing, and when carrying out monotone printing, the low density cyan ink, the high density magenta ink, and the yellow ink are used in addition to achromatic color ink.
By means of recording high density cyan ink sparsely and recording low density cyan ink densely, it is possible to reproduce comparable cyan components with these cyan inks of different density. Also, by recording high density magenta ink sparsely and recording low density magenta ink densely it is possible to reproduce comparable magenta components with these magenta inks of different density. Accordingly, these two pairs of ink are interchangeable with one another when reproducing some colors.
In monotone printing using such chromatic color inks, by using the low density inks as the chromatic color inks, it is possible to reduce the appearance of graininess in printed images. However, due to the light color of the chromatic color inks, large amounts of chromatic color ink will be consumed when printing areas of dark gray. Where the high density inks are used as the chromatic color inks on the other hand, ink consumption can be reduced. However, printed images will tend to have visible graininess.
In conventional technologies, during printing with the use of two kinds of chromatic color inks interchangeable with one another when reproducing some colors but differing in lightness as described above, the issue of how to best use these inks in order to achieve a favorable balance between ink consumption and the quality of the printed result was not taken into consideration.
The present invention is directed to printing with the use of multiple types of chromatic color inks interchangeable with one another when reproducing some colors but differing in lightness, and has as an object to provide technology whereby ink consumption may be reduced, while preserving the quality of the printed result.
The present invention is related to Japanese patent application No. 2005-47547, filed Feb. 23, 2005; the contents of which are incorporated herein by reference.